The Los Angeles Convention Center boasts the largest rooftop in Los Angeles, spanning 580,000 square feet. When the convention center needed to be reroofed in 2015, the City of Los Angeles selected BEST Contracting Services Inc., Gardena, Calif., to supply and install about 500,000 square feet of Sika Sarnafil PVC thermoplastic membrane roofing materials on several Los Angeles Convention Center buildings.
The Los Angeles Convention Center opened in 1971 and is one of the larger convention centers in the U.S., spanning 54 acres with exhibition space exceeding 700,000 square feet; meeting rooms and halls offering 147,000 square feet; a theater seating 299 patrons; and more than 1.96 million square feet of parking. The landmark has been recognized for its environmental stewardship; it is the largest convention center in the U.S. to receive LEED® EB:O+M Gold recertification.
BEST Contracting Services was tasked with reroofing the Upper and Lower Concourse roofs, South Hall roof and South and West Tower roofs.
"The project would present challenges, not only because of the magnitude of the project but also because of the sensitive nature of the facility and events it hosts," says Steven Potik, Los Angeles Convention Center building superintendent. "Detailed attention to scheduling was necessary to avoid impacting any events in progress, either by noise, dust, equipment or material staging."
BEST Contracting Services appointed Randy Ayala, senior project manager, and Ilay Mendoza, superintendent, to tackle these challenges.
The crew reroofed about 100,000 square feet on the Upper Concourse and Lower Concourse levels. The crew first removed the preexisting roof of tar and gravel then installed 1-inch-thick insulation board and a 60-mil-thick Sarnafil PVC roof system.
Tim Stratton, Los Angeles Convention Center supervisor, led weekly meetings to review dynamic issues, including safety lines and fall protection, material delivery and working around the facility's ever-changing schedule. To minimize disturbance to the public during events, the crew was limited to one access area, which required building a 10-foot ramp to transport materials to the upper level roof. The carefully orchestrated schedule allowed successful delivery of materials by crane during a two-day period.
The South Hall was the project's largest roof, spanning 400,000 square feet. Most major events take place under this roof; therefore, scheduling the work was of paramount concern.
"The sheer number of show-related semi-trucks and equipment at these events left very little space for material deliveries and created logistical challenges," Mendoza says.
Because delivery was difficult, material arrived 100,000 square feet at a time and was dispersed to the 19 different rooftop areas divided by 12-inch-high parapet walls. Inclement weather with intermittent high wind gusts required strict safety lines and fall-protection enforcement during this phase of work, as well as daily debris and trash removal.
Occasionally, crews were assigned to the night shiftsometimes with little noticeduring noise-sensitive events.
BEST Contracting Services completed this portion of the project with 3 miles of Sarnatred-V walkway, which provided access to mechanical equipment and smoke hatches.
The company completed the smallest but most complex of the sections last. The South and West Tower roofs sections totaled 14,000 square feet. Because of the tower heights and wind gusts during tear-off, debris and gravel had to be removed using a rope and wheel through the roof hatches and then through the interior of the building.
Tower height also challenged material delivery. BEST Contracting Services used an existing exterior window-washing system to hoist materials to the roof. Several employees had to get certified to operate the window-washing system.
The outcome was a white energy-efficient and environmentally friendly roof system.
Project name: Los Angeles Convention Center
Project location: Los Angeles
Project duration: October 2015 – April 2016
Roof system type: PVC thermoplastic membrane
Roofing contractor: BEST Contracting Services Inc., Gardena, Calif.
Roofing manufacturer: Sika Corp., Canton, Mass.